Pilot Light Troubleshooting Flowchart - A.O. Smith GAS WATER HEATER Installation Instructions And Use & Care Manual

Section A: Pilot light will not light (new installation).
Is the manual gas shut-off valve,
located in the supply line to the
water heater, in the on position?
YES
Have you bled all the air
NO
from the pilot tube and
gas supply line?
YES
Is the igniter producing a
YES
spark?
NO
Follow the "Testing the Igniter
System" section in this manual.
Section B: Pilot light repeatedly goes out.
Check the Base-Ring Filter and
Flame Arrestor for blockage due
to lint or dust. Are both the Air
Filter and Flame Arrestor clean?
YES
Does the flame
Reassemble the heater, press the thermal
NO
arrestor show signs
switch, and attempt to return the heater to
of discoloration?
service. Does the pilot remain lit?
YES
Shut-off the gas supply to the water heater at the
manual gas shut-off valve. Use the number on the
cover of this manual to contact Customer Service.
NO
Go to section C.

PILOT LIGHT TROUBLESHOOTING FLOWCHART

Turn the manual gas shut-off valve to
the on position and follow the lighting
NO
instructions on the front of the water heater.
While repeatedly depressing the igniter
button, push in and hold the gas control/
temperature knob until the pilot is lit and
maintains a stable flame (status light will
blink). It may take up to 90 seconds of
pilot operation before status light blinks.
Once status light blinks, release the gas
control/temperature knob.
Set thermostat to desired temperature.
Refer to the "Maintenance of
your Water Heater" section of this
NO
manual for information on cleaning
the flame arrestor and burner.
YES
Set to desired temperature.
Does the diagnostic status light on the
gas control valve/thermostat give
a two flash error code?
Refer to the "Replacing the Pilot
Assembly" instructions in the manual.
Reassemble and restore to service.
Section C: Pilot light will not remain lit.
Check for insufficient combustion air.
YES
Are the combustion air supply and ventilation openings
of sufficient size? See "Combustion Air Supply and
Ventilation" section in this manual for requirements.
YES
Does the return air duct for the furnace/
air handler/air conditioner draw its air from
the same location as the water heater?
See the "Location Requirements" section
and the "Combustion Air Supply" section.
YES
Contact a Heating and Air
Conditioning service technician
to relocate the return air duct.
The water heater's pilot can be
extinguished when the heating
or cooling system is turned on
if the return air duct is in the
same location.
NO
NOTE: If you are still experiencing diffi culties after following
the steps in sections A, B, and C, please use the number
on the cover of this manual to contact Customer Service.
YES
32
Complete this section after completing Section B.
NO
If you are still having difficulty keeping the pilot
lit, reference the number on the cover of this
manual for service information.
THERMAL SWITCH LOCATION
FIGURE 31.
Correct size of
NO
openings to allow
sufficient air.
Is there proper
drafting at the
NO
drafthood? See
"Checking the Draft"
section in this manual.
YES
Check the vent system for
restrictions/obstructions and
check the vent termination
height. Refer to the "Installation
Instructions" section of this
manual for specific requirements.
THERMAL
SWITCH